Thermostatic circuit-closer.



PATENTED DEC. 15, 1903.

R. W. W. GRIGSBY.

THERMOSTATIG CIRCUIT CLOSER.

APPLICATION FILED JUNE 15, 1903.

NO MODEL.

3 3 1 plw m y W UNITED STATES Patented December 15, 1903.

PATENT OFFICE.

REDMAN W. VrG'RIGSBST, OF CHRISNEY, INDIANA.

TH ERM OSTA'l'lC CiRCUlT-CLOSER.

SPECIFICATION forming part of Letters Patent No."747,166, dated De ember15, 1903.

Application filed June 15,1903.

T0 whom it may concern:

Be it known that I, REDMAN W. W. GRIGS- BY, a citizen of the UnitedStates, residing at Ohrisney, in the county of Spencer and State ofIndiana, have invented a new and useful Thermostatic Circuit-Closer, ofwhich the following is a specification.

This invention relates to thermostatic circuit-closers, and is designedespecially for use in connection with bearings of all sorts of machineryin which it is desirable to detect the presence of an undue amount ofheat before the bearings have become sufiiciently heated to causebinding of the journals with the bearings.

The object of the invention is to provide a simple and effective form ofthermostatic circuit-closer adapted for support upon bearings to causethe closure of a circuit through an electric hell or other signalingapparatus when the temperature of the bearings exceeds a predetermineddegree.

A further object of the invention is to provide in a thermostaticcircuit-closer of the type specified means for readily adjusting theapparatus, so that the circuit may be closed at any desired temperature.

With the objects above stated and others in view, which will appear asthe invention is more fully disclosed, the same consists in the novelconstruction and combination of parts of a thermostatic circuit-closerhereinafter described and claimed, and illustrated in the accompanyingdrawings, forming a part of this specification, in which correspondingparts are designated by the same characters of reference throughout theseveral views, it being understood that various changes in the form,proportions, and exact mode of assemblage of the elements of thecircuit-closer may be made without departing from the spirit of theinvention or sacrificing any of its advan tages.

In the drawings, Figure 1 is a diagrammatic view showing acircuit-closer in position upon a bearing and suitably connected withelectric wires leading to an ordinary electric hell or annunciatorthrough which the circuit is closed by the operation of the closer. 2 isa view in side elevation of the circuit-closer detached from thebearing. Fig. 3 is a view in vertical section through thecircuit-closer.

Serial No. 161,597. (No m0del.)l

Fig. 4: is a plan view of the circuit-closer with the cover removed.Fig. 5 is a detail view in plan of the sensitive member and itssupporting-disk.

Referring to the drawings by reference characters, 1 designates the stemof the thermostat, which is made of a tube closed at the lower end, asshown.

The numeral 2 designates the main casing of the thermostat, which isprovided at the bottom with a hollow downward extension 3, having acentral opening within which the stem 1 is brazed. The extension fromthe casing terminates in a reduced threaded portion 4, above which areformed a plurality of shoulders 5 for the engagement of a Wrench. Thecasing 2 is open at the top and is provided with a seat for a cover 6,which fits down over the open top of the casing and is held againstanyturning movement by means of ribs 7, provided at opposite sides of theeasing 2 and entering slots in the downwardlyprojecting flange of thecover. At the top of each of the ribs 7 there is a rounded notch 8,which corresponds to a similar notch 9,formed at the top of each of theslots in the cover that engage with said ribs. The notches 8 and 9 inthe casing-cover combine to form approximately circular openings for thepassage of the wires (designated generally as W) which lead to thesignal sounded by closing the circuit through the thermostat.

The entire interior of the casing, stem, and cover is lined withinsulating material of any suitable kind, such as leather board or someother compact cellulose-fiber material. The lining comprises,preferably, a small disk 10 at the bottom of the stem, a tube 11,fitting within the bore of the stem, a disk 12, resting upon the bottomof the casing 2 and having a central opening through which passes theupper end of the tube 10, a ring 13, lining the side wall of the casing,a ring 14, lining the side wall of the cover, and a disk 15, lining theunder surface of the top of the cover.

Withinthecasingavhhitsinsulating-lining, is supported a thermostatcomprising a disk 16, of thin metal of any suitable kind, and asensitive member consisting of a narrow loop 17, made of a compoundstrip of metal one side of which is composed of a metal having adifferent rate of expansion from that composing the other side. Themetal having the higher rate of expansion will form the outer surface ofthe loop and that having the lower rate the inner surface of the loop,so that when the temperature of the loop rises the greater expansion ofthe metal forming the outer suri'ace thereof will force the ends of theloop together. The disk 16 has one end of the loop 17 soldered thereto,as best seen in Fig. 5, and the other end of the loop extends upwardthrough a central opening in the disk to terminate in a small plate 18,of platinum, which is supported a little above the disk 16. The disk 16is attached by means of screws 19 to a disk 20, of tolerably thickinsulating material, which has a central opening registering with theopening in the disk 16, and on the upper surface of the disk 20 areriveted terminal plates 21 and 22, each of which is preferably ofsegmental form, as shown, and the former of which is provided with anupwardlyprojecting ing 23, having a threaded opening through whichextends a screw 24, having a platinum tip 25, which is directed towardthe platinum plate 18 at the free end. of the loop 17. The terminalplate 22 is electrically connected with the disk 16 by means of a bolt26, which extends through the terminal plate, the disk 20, and the disk16. Binding-screws 27 are provided one on each of the plates 21 and 22and serve to bind the wires W to the terminal plates. In order toprevent electrical contact of the rivets by means of which the terminalplates are secured to the disk 20 with the disk 16, a disk of thininsulating material 28 is introduced between the disks 16 and 20.

The disk 28 is held in proper relation to disks 16 and 20 by screws 19,which have heads countersunk in the under side of disk 16 and the upperends of which lie flush with the upper surface of the disk 20.

In order to prevent turning of the disk 20 and the members associatedtherewith inside the casing 2, the bottom of the casing 2 is pierced bythreaded openings, and screws 29, mounted therein, extend upward throughsuitable openings in the disks 12, 28, and 20, the disk 16 havingportions of its material cut away surrounding the screws 29 to preventelectrical contact therewith.

When the circuit-closer is in use, the stem will be introduced into anopening formed for that purpose in a bearing-block, as shown in Fig. 1,and the wires i/V will be introduced through the openings provided forthat purpose in the upper margin of the side wall of the casing 2 andattached by means of the binding-screws 27 to the terminal plates 21 and22. The screw 24c will then be turned until the platinum tip on thepoint thereof comes into contact with the platinum plate 18 on the freeend of loop 17, when the bell to which the wires W lead will start toring. If the bearing is running cool, the screw 24 will then be turnedin the opposite direction to withdraw the tip thereof from contact withplate 18, and as soon as the bell ceases to ring the circuit-closer willbe set. If now any increase of temperature occurs in the bearing, theexpansion of the metal forming the outer surface of the loop 17 at agreater rate than that forming the inner surface will cause the free endof the loop bearing the platinum plate 18 to move into contact with theplatinum tip of screw 24 and close the circuit, setting the bell toringing again and indicating the presence of increased heat in thebearing soon enough for the machinery to be stopped and the trouble ofWhatever charactercorrected before the heat becomes so intense as to doserious damage, such as melting the Babbitt or other antifriction metalof which the bearings may be formed.

In applying the circuit-closer to bearings it is desirable that the endof the stem 1 may always rest upon the Babbitt metal or otherantifriction metal forming the interior surface of the bearings, and forthis reason the circuit-closers will be made with stems of differentlengths, so that the contact of the stem with the lining of the bearingsmay be insured.

When a large number of circuit-closers are used in connection with acomplicated machine plant, it will be desirable to have thecircuit-closers connected with an audible and with visible signals, sothat the presence of too high temperature in any of the hearings may bemanifested by an audible signal, and the location of the heated bearingindicated by a visible signal; but in view of the fact that the natureof the signals which are employed in connection with the circuit-closeris not a part of this invention any detailed description of such signalsis regarded as unnecessary.

Having thus described the construction and operation of my invention,what I claim as new, and desire to secure by Letters Patent, 1s-- 1. Ina thermostatic circuit-closer having a casing provided with a hollowstem for insertion into an opening in a bearing-block or the like, apair of terminal plates one of which has electrically connectedtherewith one end of a loop disposed within the stem and formed ofstrips of nnequally-expansible metal and the other of which has anadjustable member disposed opposite to the free end of said loop.

2. In a circuit-closer having a casing and a hollow stem adapted forinsertion into an opening in a bearing-block or the like, a pair ofterminals to one of which is electrically connected one end of the loopformed of strips of unequally-expansible metal said loop being disposedwithin said hollow stem, and to the other of which is attached a lugbearing a screw with which the free end of said loop is adapted tocontact.

3. In a circuit-closer having a casing and a hollow stem adapted forinsertion into an opening in a bearing-block or the like, anoncondncting lining for said casing and stem, a

disk of non-conducting material within said 1 the terminal insulatedfrom said loop and dicasing, a pair of terminal plates provided on Irected toward the free end of said loop.

the upper side of said disk of non-conducting In testimony that I claimthe foregoing as material, a disk of metal electrically connectmy own Ihave hereto affixed my signature in 5 ed with one of said terminals andsecured to the presence of two witnesses.

the under side of said disk of non-conducting material, a thin loopformed of strips of une- REDMAN GRIGSBY' qnally-expansible metalelectrically connect- WVitnesses:

ed with said metallic disk and disposed with- HENRY KRATZ, 10 in saidhollow stem, and a screw carried by ED BILLART.

